Conventional medical electrodes generally include a conductive electrode member and an electrical conductor that provides an electrical interface between the electrode and various types of medical equipment, such as monitoring equipment and stimulating equipment. Illustrative monitoring equipment includes electrocardiograph (ECG) monitors and illustrative stimulating equipment includes transcutaneous stimulation equipment and defibrillators.
Some known electrodes, referred to as multifunction electrodes, are designed to meet the requirements of different types of medical equipment so that the electrodes can be used for various medical procedures without requiring removal from the patient. For example, defibrillation electrodes deliver high energy levels, such as in the order of 360 Joules, over a relatively large area of the patient's skin, such as 50 cm2 per electrode, in order to achieve sufficient current density distribution for restoring normal heartbeat rhythm. Challenges in designing defibrillation electrodes include avoiding irritation and burning of the patient's skin due to the high current density around the perimeter of defibrillation electrodes. Monitoring electrodes on the other hand are generally smaller, such as on the order of a few cm2, and need to carry only very low level electrical signals in the order of milliamps. In order to permit X-ray examination without requiring removal of electrodes, X-ray transmissivity (referred to also as X-ray translucency and X-ray transparency) is a desirable characteristic for multifunction medical electrodes. Multifunction electrodes described in a U.S. Pat. No. 5,824,033 entitled “Multifunction Electrode” are optimized to meet these and other desirable characteristics of multifunction medical electrodes.
One of the difficulties in manufacturing medical electrodes has been attachment of the electrical conductor which is generally in the form of a multi-strand wire or fiber. In the electrodes described in the above-referenced U.S. Pat. No. 5,824,033 and others, generally, the individual conductor strands are spread, or fanned out and attached to a current distributing mat which, in turn, distributes current over a central area of the electrode member. However, fanning out the individual conductor strands is a manual process which is time consuming and costly.